This invention relates to photographic objective lens systems having a relative aperture of at least f/2.0 and field angle as wide as 44.degree., and more particularly to a photographic objective lens system adapted for use with a diaphragm located outwardly of the entire lens system while nevertheless an excellent state of correction of the image aberrations is preserved even in such situation.
The commonly known photographic objective lens systems are designed so that the diaphragm is located within an air space of the lens system, and, therefore, the entrance and exit pupils lie inside of the lens system. In some special photography, however, it is required for the objective lens to have a pupil lying outwardly thereof. For example, with specially designed cameras, it is desired because of the arrangement and construction of the mechanism thereof to position the shutter, diaphragm and the like in front of the objective lens. In this case, there is required the front diaphragm type of objective lens.